1. Field of the Invention
This invention relates to a mixing valve and its change valve which is selectively switched to provide hot water either to a shower or to a bath.
2. Description of the Prior Art
A vertical sectional front view in FIG. 10 and a vertical sectional side view in FIG. 11 show a conventional type of a mixing valve. In the valve case 1, a hot water chamber 2, a water chamber 3 and a mixing chamber 4 are aligned. In crossing the hot water chamber 2 and the water chamber 3, a temperature control valve with a thermostat 5 is arranged to obtain hot water at a desired temperature by controlling the rate of hot water from the hot water chamber 2 and water from the water chamber 3 into the mixing chamber 4. At the right end of this valve case 1, a thermo handle 7 is fixed to adjust the axial position of a spindle 6 in the thermo handle 5 and determine the temperature of hot water.
At the bottom of the mixing chamber 4, a change valve chamber for hot water 8 connected to the mixing chamber 4 is installed to project therefrom. In this change valve chamber 8, a supply port to a bath 9 and a supply port to a shower 10 are aligned, its opening and closing being controlled by the change valve 11. The change valve 11 has valves 13 and 14 which are interfittingly attached to a spindle 12, and generally the valves 13 and 14 are spaced from one another with a spring 15. When a change handle 16 is operated to turn to the right or to the left, the spindle 12 moves forward and backward (move to the right or to the left in FIG. 11) by the screw 17, thereby either valve 13 or valve 14 is operated to open, that is, change valve chamber 8 is connected to either supply port to a bath 9 or supply chamber to a shower 10 and hot water adjusted to a desired temperature in the mixing chamber 4 is provided to the bath or to the shower.
This conventional type of mixing valve has some defects : the first one is the irregular appearance of the valve case 1, i.e. the change valve chamber 8 is formed to project at the central bottom of the valve case 1; the second one is the increase in height of the valve case 1; the third one is the unsymmetrical form of the valve case, where one end of the valve 1 is equipped with the thermo handle 7 and the other end is closed; and the last one is the axial enlargement of all the members composing the change valve 11 and the increase of the depth of the valve case, which result from the working space between the valve 13 and the valve 14 for opening and closing the change valve 11 and the area required to move the spindle 12 forward and backward to, open and close the valves 13 and 14.